Interfacial heat transport in open channel turbulent flows is strongly dependent on Surface waves that can appear as a result of the interaction of bulk turbulence with the free surface. The paper describes wave/heat transfer phenomena in inclined turbulent open surface water flows. The experiments were conducted in a regime of transition from "weak" to "strong" turbulence. in which the stabilizing influences of gravity and surface tension are relatively small against the disturbing effects of turbulence. A key role of the Fronde number, Fr-perpendicular to, built through the surface-normal component of g has been revealed. As Fr-perpendicular to, grows, the wave amplitude grows, and the frequency spectrum shifts towards shorter waves. These changes lead to a heat transfer improvement, enough to double the heat transfer coefficient. The experimental data have been compared with calculations based on a "K-epsilon" model. As a result, the range of applicability of the standard model has been established as Fr-perpendicular to < 2000, The turbulent Prandtl number has been evaluated for Fr-&BOTTOM; < 700. (C) 2003 Elsevier Ltd. All rights reserved.